Squashed 'libs/cli11/' content from commit dcbcb47

git-subtree-dir: libs/cli11
git-subtree-split: dcbcb4721dda5dab0a56d9faaaee50e6a30f7758

.appveyor.yml

@@ -0,0 +1,38 @@
+version: 2.2.0.{build}
+
+branches:
+  only:
+    - main
+    - v1
+
+install:
+  - git submodule update --init --recursive
+  - py -3 --version
+  - set PATH=C:\Python38-x64;C:\Python38-x64\Scripts;%PATH%
+  - cmake --version
+  - python --version
+  - python -m pip --version
+  - python -m pip install conan
+  - conan user
+  - conan --version
+
+build_script:
+  - mkdir build
+  - cd build
+  - ps:
+      cmake .. -DCLI11_WARNINGS_AS_ERRORS=ON -DCLI11_SINGLE_FILE_TESTS=ON
+      -DCMAKE_BUILD_TYPE=Debug -DCMAKE_GENERATOR="Visual Studio 14 2015"
+  - ps: cmake --build .
+  - cd ..
+  - conan create . CLIUtils/CLI11
+
+test_script:
+  - cd build
+  - ps: ctest --output-on-failure -C Debug
+
+notifications:
+  - provider: Webhook
+    url: https://webhooks.gitter.im/e/0185e91c5d989a476d7b
+    on_build_success: false
+    on_build_failure: true
+    on_build_status_changed: true